This invention relates to a metering dispenser which, in fluid dispensing work in which the fluid inside a supply tank is supplied to the metering dispenser by a single-shaft eccentric screw pump, etc., and then applied by said metering dispenser, ensures that the amount of the fluid dispensed from said metering dispenser is in accurate proportion to the revolution speed of the metering dispenser pump, and it especially relates to a metering dispenser which is well-suited for the metered dispensing of fluids such as high-viscosity fluids and adhesives in combination with a robot device. In addition, this invention also relates to an improved version of a shaft seal device for the motor drive shaft of the aforementioned type of metering dispenser.
If the fluid supply tank and the metering dispenser are separated at a considerable distance, or if the fluid is being supplied to multiple metering dispensers simultaneously, it is necessary to use a supply tank pump which has a greater dispensing pressure than that of the metering dispenser pump(s) in order to supply the fluid to the metering dispenser(s). However, in this type of situation, it is common to use a displacement pump, in which the dispensing rate is in direct proportion to the pump's rotor revolution speed, for both the supply tank pump and the metering dispenser pump(s).
In accordance with the prior art, as shown in FIG. 5 herein, a pressure sensor 12 provided on the metering dispenser D will detect the internal pressure in order to regulate the output of the pump 13 of the supply tank 15 so that the pressure inside the metering dispenser D is maintained within the specified pressure range. Note that, in FIG. 5, the numeral 4 indicates a single-shaft eccentric screw pump, 4c is a nozzle, 5 is the drive motor of the pump 4, 14 is the drive motor of the pump 13, and 16 is a control device.
In addition, the shaft seal device commonly used for the shaft seal of the drive shaft 5a of the pump 5 consisted of, as shown in FIG. 6, a construction in which multiple packing rings 20 were mounted between the end of the drive shaft 5a and the shaft seal 18 through which said drive shaft 5a passed, and this construction was intended to prevent any leakage.